European Lisp Symposium 2009: Keynote (03 Jun 2009)

Scott joked he might well be the Zelig or Forrest Gump of the Lisp community, after having been around for a long time and making appearances in a number of (unlikely?) places. In amusing anecdotes, he explained some of the key learnings he took away during his career, and what those learnings might mean for the future of Lisp and the Lisp community.

Some notes (from memory, hence most certainly inaccurate):

• "Any bozo can write code" - this is how David Moon dismissed Scott's attempt to back up one of his designs with code which demonstrated how the design was meant to work.
• "Total rewrites are good" - Scott was the designer of CLIM, which underwent several major revisions until it finally arrived at a state he was reasonably happy with.
• "If you cannot describe something in a spec, that's a clue!" - amen, brother!
• "The Lisp community has a bad habit of building everything themselves"
• "Immutability is good" (even for single-threaded code)
• "Ruby on Rails gets it right"; only half-jokingly, he challenged the community to build something like "Lisp on Rails". Later during the symposium, I learned that we already have Lisp on Lines ("LoL" - I'm not kidding you here ).
• "Java + Eclipse + Maven + XXX + ... is insane!" - and later "!J2EE got it spectacularly wrong"
• He reminded us that the Lisp Machine actually had C and Fortran compilers, and that it was no small feat making sure that compiled C and Fortran programs ran on the system without corrupting everybody else's memory. (I'd be curious to learn more about this.)
• Lisp code which was developed during Scott's time at HotDispatch was later converted to Java - they ended up in roughly 10x the code size.
• The QRes system at ITA has 650000 lines of code, and approx. 50 hackers are working on it. Among other things, they have an ORM layer, transactions, and a persistence framework which is "a lot less complicated than Hibernate".
• Both PLOT and Alloy were mentioned as sources of inspiration.

Scott then went on to develop a list of features which a future version of Lisp, dubbed Uncommon Lisp, should have. That list was pretty long; notable features which I remember were:

• Should run on a virtual machine
• Good FFI support very important
• Support for immutability
• Concurrency and parallelism support
• Optional type checking, statically typed interfaces (define-strict-function)
• "Code as data" not negotiable

Not surprisingly, Clojure was mentioned quite often, both during the keynote and in the subsequent Q&A session. I'm still not quite sure what Scott's position on Clojure really is. To me, most of the points he made seemed to actually back up design decisions in Clojure: For instance, Clojure runs on a VM, reuses the libraries and tools of the underlying platform, connects easily to other languages, makes a decided effort to support concurrency well, and while it breaks with Common Lisp syntax, it is still in the Common Lisp spirit of being a pragmatic implementation of the fundamental Lisp ideas. On the other hand, Scott also criticised some Clojure details (name resolution comes to mind), and seemed uncertain whether to full-heartedly recommend everyone to join the Clojure camp right away.

I think what Scott tried to get across is that a revolutionary approach is both possible and worthwhile for the Lisp community. Revolution, of course, means breaking with the past, and it became obvious during Friday's panel discussion on the future of Common Lisp that not everybody at the symposium felt comfortable with the thought.

PS: Michele Simionato discusses the keynote presentation from a Schemer's point of view.